Shockproofing mechanism



G. H. SYROVY SHOCK-PROOFING MECHANISM Filed May 25, 1944 WW .\0 PPM? y oms t H t W6 A am H, e G

AMA

Patented Aug. 20, 1946 SHOCKPROOFING'MECHANISM Gerald H. Syrovy,Philadelphia, Pa., assignor to General Electric Company, a corporationof New York Application May 25, 1944, Serial No. 537,338

9 Claims. 1

My invention relates to improvements in shockproofing mechanisms andmore particularly to mechanisms for preventing the false operation ofdevices such as circuit breakers, relays and the like in consequence ofshocks without interfering with the intended operation of the devicesmaterially longer than the duration of the shock.

Devices, such as circuit breakers, relays and the like, which areintended to function under abnormal conditions of an electric circuitare liable to operate falsely under shock conditions.

On board warcraft, especially in time of battle, such shock-producedfalse operations could prove extremely crucial by effecting thedeenergization of motors and other apparatus so critically needed inoperation. In order to prevent such false operations, variousarrangements have been proposed and many actually used. Most of thesearrangements interfere with or actually prevent the intended faultresponsive operation of the devices since they leave the devicesindefinitely locked against operation. Other arrangements which do notmaterially interfere with the intended operation of the devices areeither too dependent on the human element or else too complicated toapply to existing circuit breaker and relay structures.

An object of my invention is to provide for devices such as circuitbreakers, relays and the like an improved shock-proofing mechanism whichprevents false operation of the devices under shock conditions withoutmaterially interfering with the intended operation of the devices.Another object of my invention is to provide a shock-proofing mechanismwhich operates automatically on the occurrence of shock conditions toprevent false operation of the device to which it is applied. A furtherobject of my invention is to provide an automatic shockproofingmechanism which has a relatively simple structure readily applicable texisting circuit breaker and relay structures, These and other objectsof my invention will appear in more detail hereinafter.

In accordance with my invention, I provide for circuit breakers, relaysand the like a shockproofing mechanism which comprises a resilientlypendulously supported weight which is arranged normally readily topartake of the movement of a critical shock-susceptible member of thedevice but is restrained against such movement during shock conditionsin consequence of the deflection of the operating means. Also inaccordance with my invention, I provide a shockproofing mechanism whichis readily applicable to existing circuit breaker and relay structures.

My invention will be better understood from the folloiwng descriptionwhen considered in connection with the accompanying sheet of drawings,and its scope will be pointed out in the appended claims.

In the accompanying sheet of drawings, Fig. 1 illustrates ashock-proofing mechanism embodying my invention as applied to atrip-free air circuit breaker, and Fig. 2 illustrates an embodiment ofmy invention as applied to an electromagnetically actuated device.

In Fig. 1, I have illustrated an embodiment of my invention as appliedto an automatic tripfree circuit breaker mechanism such as disclosed inUnited States Letters Patent 2,152,453, issued March 28, 1939. As shown,this mechanism comprises a main operating toggle consisting of links Iand 2 pivotally joined at 3. This toggle is arranged to be actuated by arotatably mounted handle 4, the rotation of which turns a crank 5 tomove a reciprocably guided crosshead 6.

This is connected to the crank pin of the crank 5 by a link I and to thetoggle joint pin 3 by a link 8. The toggle link I is pivotally connectedby a pin 9 to a link l0 mounted on a stationary pivot II. The togglelink 2 is pivotally connected by a pin [2 to a crank I3, which isrotatable on a fixed shaft I4.

The crank I3 has two rigidly interconnected, parallel arms l5 and I6through which th shaft I4 extends. The arm I5 is connected to the togglelink 2 and the arm l6 is rovided with a cam surface IT. This cam surfaceis arranged to coact with a contact operating crank l8, which is rigidlyconnected through a rotatable suitably insulated counter shaft H] to themovable contact carrying arm 20 of the circuit breaker. When the crankI3 is rotated clockwise by straightening the operating toggle I-2 inresponse to elevation of the crosshead 6, th cam face I! bearing on aroller 2| on the crank 18 rotates the counter shaft [9 counterclockwiseto bring the movable contact structure 22 of the circuit breaker intoengagement with the stationary contact structure 23, 24.

In order to hold the toggle I--2 at the pivot 9 in thrust transmittingposition relatively to the crank l3, there is associated with the toggleguide link it] a latching and tripping means comprising a link 25, whichis connected to the pin 9 and to a latch 26 mounted on a fixed pivot 21.The link 25 and the latch 26 are so interconnected at 28 as to insure aforce reducing connection, Coacting with the latch 26 is a, rotatable 3tripping shaft 29 to which is secured a detent member adapted to engagethe tail 3! of the latch 25.

In the position shown, collapse of the toggle l2, that is,counterclockwise rotation of the pivot pin 9 and tripping of the togglejoint 3, is restrained by the latch 26 and the detent 30. Trippingmovement, that is, counterclockwise rotation of the tripping shaft 29,efiects release of tion of the mechanism. The prop 32 is also biased forcounterclockwise rotation by suitable means, such as a, torsion spring35.

The tripping shaft 29 is provided with an arm whereby it can be rotatedcounterclockwise to the releasing position. by suitableelectroresponsive means, such as the tripping plunger 31 of anelectromagnet 38 which may be energized, for example, in response to thecurrent flowing through the circuit breaker, as is well known to theart. Clockwise rotation of the tripping shaft is limited by a stop 39.

The contact operating crank i8 is connected to the crank I 3 by means ofa compression spring 43, which is guided on a member 4| engaging one endof the crank l3 and having a guided sliding connection at 42 with thedownwardly extending arm 43 of the crank I8. In the closed circuitposition shown, the spring 49 is under compression so that immediatelyupon elease of the tripping latch, the collapse of the toggle l--2 isaccelerated by the energy stored in the spring whereby to effect rapidmovement of the cam surface I1 away from the roller 2|. The contactoperating crank I 8 is also acted upon throughout the open.- ingmovement by the spring 49, tending to accelerate the separation of thecontacts 22, 23 and 24. During the closing operation when the crank i3is rotated clockwise, the spring is placed under compression by reasonof the comparatively long lever arm 43 of the crank 18 acting inopposition to the spring.

When the toggle [-2 is released in response to a tripping operation, thepivotpin 9 is free to rotate counterclockwise about pivot II. Thiscauses a shift of the toggle joint 3 from the end of the prop 32 andpermits a free collapse of the toggle. When this occurs, the pivot 9reverses its movement and drops so that the latch 26 can return to itsinitial position. During this return movement, the nose 3| of the latchrides over the latch detent 39 and resets to the position illustrated inFig. 1, The prop 32 is suitably shaped, as illustrated, for permittingfree movement of the toggle joint 3 alongside the prop.

The resilient connection 34 between the trip shaft 29 and the prop 32biases the tripping detent into latching engagement after the latch 26,in dropping, pushes down on and passes by the latch detent 3|, thelatter snapping into reset position due to the bias of the spring 34. Atthe same time, the spring 34 and the spring 35 exert a counterclockwisebias on the prop 32 urging it against the side of the link 8 so that,when the links I and 2 are raised to toggle position in a subsequentclosing operation, the prop 32 is snapped 4 beneath the toggle joint 3to hold the mechanism in the closed position independently of theactuating handle 4. A stop member 44 is provided for preventingcounterclockwise movement of the prop beyond the toggle joint 3.

Since the maintenance of the circuit closing position f the circuitbreaker just described is dependent on the engagement of the nose 3! ofthe latch 26 by the detent 30 on the tripping shaft 29, it will beobvious that something further must be provided to insure thiscooperative latching relationship under shock conditions of such acharacter and intensity as to effect the release of the latch .26. Inorder to prevent such release, I provide, in accordance with myinvention, means for preventing a movable controlling member such as thetripping shaft 29 from changing its position .under shock effects. Asshown in Fig. 1, this shock-proofing means comprises a Weight 45 whichis resiliently pendulously supported from the tripping shaft 29 so as topartake of the movement thereof. For this purpose, the weight 45 may bemounted on a resilient member such s a piece of spring wire 46 whichobviously is defiectable in any direction. This wire has a transverseloop in which rides a pin l? mounted in a crank 48 which is suitablysecured to the tripping shaft 29 so asto rotate therewith, Thelongitudinal axis of this tripping shaft 29 is indicated in extension bythe dashdot line 49.

Further in accordance with my invention, I provide means dependent onthe deflection of the supporting element 45 in consequence of shock-orthe like, which causes material movement of the weight 45, forpreventing movement of the tripping shaft 29 from its latching position.As shown in Fig. 1, this means comprises a relatively stationary part 59mounted intermediate the tripping shaft 29 and the weight 45. Inaccordance with my invention, this stationary part 50 is provided with ahole 5! through which the wire 45 passes. Moreover, the configuration ofthis hole 5| is such as to permit the wire 46 to move freely lengthwisetherein except when the wire is deflected by movementof the weight 45 inconsequence of shock and the like. In the arrangement shown in Fig. 1,the hole is generally funnel shaped with the wider end toward the weight45. In one application of my invention, I have obtained satisfactoryoperation with a steel. wire about 0.040 inch in diameter with thediameter of the opening of the upper part of the hole 5| about 0.042inch. With such a wire, a Weight of about ounce so positioned on thewire as to resonate at from 40 to 50 cycles per second is satisfactoryfor some applications. The resonance can, of course, be varied bychanging the position of the weight on the wire. The size of the wire 46relatively to the Weight 45 is such that the wire is stiff enough not tobe deflected by the pitching or tossing of a ship sufficiently to causea trip locking ction.

In order to limit the amplitude of the swing of the weight 45 so as toavoid a permanent set of the wire 46 under voilent shocks and alsoto-prevent the weight from interfering with adjacent parts, I providesuitable means such as a stationary cylindrical member 52, the wall ofwhich surrounds the weight 45 and which has a, diameter sufiicient tomaintain the displacement of the weight 45 within desired bounds.

Assuming the parts positioned as shown in Fig. 1, then as long as thereis no shock the wire 46 is straight and free to move up and down in thehole 5| without material interference with the movement of the trippinshaft 29. Such interference as there is is merely that due to the weightof the additional portions 45, 46, 41 and 48. This, of course, can bereadily compensated by adjustment of the spring C s qu t in case of anabnormal circuit condition causing the operation of the tripping plunger31, the circuit breaker will be opened by the actuation of the trippingshaft 29 just the same as though my shock-proofing mechanism were notpresent. In other words, no interference with the operation of thecircuit breaker appears either under normal or abnormal circuitconditions. If, however, a shock occurs of such magnitude as to tend torelease the tripping shaft 29 and thereby open the circuit breaker, theweight 45 will be given an actuating impulse such as to cause vibrationof the wire 46 at its resonant frequency. When the wire is set intovibration, it ceases to remain straight andbends more or less into theshape of the configuration of the hole 5i oscillating back and forthlike a pendulum. Obviously, as long as the wire is not straight, itcannot be pulled upwardly through the narrow portion of the hole EI and,consequently, movement of the shaft 29 in the tripping direction,counterclockwise as viewed in Fig. 1, cannot occur. Moreover, since thedevice is purely automatic, the shock-proofing effect is availablewithout any attention from the operating personnel. 'If an abnormalcircuit condition occurs while the wire 46 is in vibration, the trippingof the circuit breaker will be delayed for the relatively short periodof time required for the weight 45 to come practically to a standstillso that the wire 46 is straight long enough to be moved upwardly throughthe hole 5| into the releasing position of the tripping shaft 29.Ordinarily, this delayed period of tripping, while suflicient to preventfalse tripping on shock, is not material to the opening of the circuitbreaker under fault conditions.

In Fig. 2, I have shown an embodiment of my invention in anelectroresponsive device such as an undervoltage or overcurrent relay.As illustrated, this relay comprises an electromagnet having astationary magnetic core 53, an energizing windin 53a, and an armature54 secured to a controlling member 55 pivoted at 56. In the specificarrangement shown, the controlling member 55 is arranged to control themovement of a contact5'l in dependence on the energization of thewinding 53a or, more properly speaking, the resultant of the attractiveeffect on the armature 54 and the opposing effect of a biasing spring58. While the controlling member 55 is shown as an actuator for thebridging contact 51 relatively to the cooperating stationary contacts59, it could, of course, be arranged to trip a circuit'breaker or forother purp0ses,as will be apparent to those skilled in the art.

Inasmuch as a relatively light shock might be suflicient to release thearmature 54, particularly if the voltage or'current energizing thewinding 53a; happens to be close to the releasing value as determined bythe biasing spring 58, a false operation of the relay could readilyoccur. In order to prevent such false operation, the relay is providedwith a shock-proofing mechanism similar to that illustrated in Fig. 1with the resilient supporting member or wire 46 looped around a pin (itmounted to move with the controlling member 55. With this arrangement,it will be obvious that, as long as the resilient support 46 isstraight, the armature 54 is free to move in accordance with the purposefor which itwas designed to operate. However, in case of shock, thedeflection of the supporting wire 46, in consequence of the impulsegiven to the weight 45, will prevent the movement of the wire throughthe opening 5| as lon as the oscillation of the wire 46 is maintained.As soonas the wire becomes sufficiently straight to move through theopening 55, the armature 54 is free to move in case the abnormalcondition for which it is intended to operate is present.

From the foregoing, it'will be apparent that shock-proofing mechanismsembodying my invention are purely automatic and that they do notmaterially interfere with the device in the event of an abnormal circuitcondition occurring more or less coincidentally with the shock itself.Furthermore, it will be obvious from the simplicity of the device andits structure that it is readily applicable to existing devices, such ascircuit breakers, relays and the like, without material modification intheir structure or such space requirements as would make it impracticalin application.

Whi1'e I have shown and described my invention in considerable detail, Ido not desire to be limited to the exact arrangements shown, but seek tocover in the appended claims all those modifications that fall withinthe true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A device to be maintained in a predetermined condition, a movablecontrolling member operative in one position to maintain the device insaid predetermined condition but subject to change of position by shock,and means for preventing such change of position comprising a weight, aresiliently pendulous support for said weight defiectable in anydirection and arranged to partake of the movement of said member, andmeans dependent on the deflection of said support in any direction inconsequence of shock or the like for preventing movement of said weightin a direction to allow movement of said member from said one position.

2. A device to be maintained in a predetermined condition, a movablecontrollin member operative in one position to maintain the device insaid predetermined condition but subject to change of position by shock,and means for preventing such change of position comprising a weight, aresilient element pendulously supporting said weight to partake of themovement of said member, and stationary means provided with a holethrough which said element passes, the configuration of said hole beingsuch as to permit said element to move freely lengthwise therein exceptwhen the element i deflected by movement of the weight in consequence ofshock and the like.

3. A device to be maintained in a predetermined condition, a movablecontrolling member operative in one position to maintain the device insaid predetermined condition but subject to chang of position by shock,and means for preventing such change of position comprising a springwire mounted to partake of the movement of said member, relativelystationary means provided with a generally funnel shaped hole throughwhich said wire passes, and. a weight mounted on said wire beyond thewider end of said hole.

4:. An electromagnet comprising an armature and means for preventing therelease of said armature from the attracted position in consequence ofshock comprising a weight, a resiliently 'pendulous support for saidweight deflectable in any direction and arranged to partake of themovement of said armature, and means dependent on the deflection of saidsupport in any direction in consequence of shock or the like forpreventing movement of said weight in a direction to allow movement ofsaid armature from said one position.

5. A, circuit breaker tripping mechanism comprising a tripping member, asingle resilient element supported from said tripping member anddeflectable in any direction, a weight mounted on said resilientelement, and means dependent on the deflection of said resilient elementin any direction in consequence of shock or the like for preventing ashock actuated tripping operation of said tripping member.

6. A circuit breaker tripping mechanism comprising a tripping shaftrotatable in one direction to eifect the tripping of the circuit breakerand means for preventing a shock actuated tripping rotation of saidshaft comprising a spring wire supported from said tripping shaft,relatively stationary means provided with a generally funnel shaped holethrough which said wire passes, and a weight mounted on said wire beyondthe wider end of said hole.

7. A device to be maintained in a predetermined condition, a movablecontrolling member operative in one position to maintain the device insaid predetermined condition but subject to change of position by shock,and means for preventing such change of position comprising a weight, aresiliently pendulous support for said weight arranged to partake of themovement of said member and to vibrate at a predetermined frequency whensubjected to a severe shock, and means dependent on the deflection ofsaid support in consequence of shock or the like forpreventing movementof said member from said one position.

8. A device to be maintained in a predetermined condition, a movablecontrolling member operative in one position to maintain the device insaid predetermined condition but subject to change of position by shock,and means for preventing such change of position comprising a weight, a,resiliently pendulous support for said weight arranged to partake of themovement of said member and to vibrate at a predetermined frequency whensubjected to a severe shock, means dependent on the deflection of saidsupport in consequence of shock or the like for preventing movement ofsaid member from said one position, and means for limiting the amplitudeof the vibration of said support.

9. An arrangement for preventing movement of a member subject to changeof position by shock, comprising a weight, a single resilientlypendulous support for said weight deflectable in any direction andadapted to be connected to said member, and means dependent on thedeilection of said support in any direction in consequence of shock orthe like for preventing'movement of said weight in a direction to allowmovement of the member by shock.

GERALD H. SYROVY.

